DOCSLIB.ORG

Drivers of Evolutionary Change in Podospora Anserina

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Drivers of Evolutionary Change in Podospora Anserina Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology 1923 Drivers of evolutionary change in Podospora anserina SANDRA LORENA AMENT-VELÁSQUEZ ACTA UNIVERSITATIS UPSALIENSIS ISSN 1651-6214 ISBN 978-91-513-0921-7 UPPSALA urn:nbn:se:uu:diva-407766 2020 Dissertation presented at Uppsala University to be publicly examined in Ekmansalen, Evolutionary Biology Centre (EBC), Norbyvägen 18D, Uppsala, Tuesday, 19 May 2020 at 10:00 for the degree of Doctor of Philosophy (Faculty of Theology). The examination will be conducted in English. Faculty examiner: Professor Bengt Olle Bengtsson (Lund University). Abstract Ament-Velásquez, S. L. 2020. Drivers of evolutionary change in Podospora anserina. Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology 1923. 63 pp. Uppsala: Acta Universitatis Upsaliensis. ISBN 978-91-513-0921-7. Genomic diversity is shaped by a myriad of forces acting in different directions. Some genes work in concert with the interests of the organism, often shaped by natural selection, while others follow their own interests. The latter genes are considered “selfish”, behaving either neutrally to the host, or causing it harm. In this thesis, I focused on genes that have substantial fitness effects on the fungus Podospora anserina and relatives, but whose effects are very contrasting. In Papers I and II, I explored the evolution of a particular type of selfish genetic elements that cause meiotic drive. Meiotic drivers manipulate the outcome of meiosis to achieve overrepresentation in the progeny, thus increasing their likelihood of invading and propagating in a population. In P. anserina there are multiple meiotic drivers but their genetic basis was previously unknown. In Paper I, we demonstrated that drive is caused by members of the Spok gene family. We discovered two new Spok genes, Spok3 and Spok4, which locate in different chromosomes in different strains. In Paper II, we showed that Spok3 and Spok4 are found on a gigantic (up to 247 Kb long) variant of Enterprise, a Crypton-like transposable element. Enterprise likely mobilize through the action of a putative tyrosine-recombinase that we call Kirc. When carrying the Spoks, this element has double selfish properties: transposition and meiotic drive. In addition, we found that homologs of the Spoks (Paper I) and of Kirc (Paper II) are widespread in fungi but their phylogenies are discordant with that of the species, suggesting that they have undergone horizontal gene transfer. In Papers III and IV, I turned the focus into genes that have an adaptive function. In fungi, the het genes control conspecific self/ non-self recognition. Such genes are expected to evolve under frequency-dependent balancing selection. In Paper III, we found evidence of balancing selection acting on some het genes across the P. anserina species complex. Unexpectedly, we also discovered that het genes of the HNWD gene family are duplicated in a transposon-like manner, broadening our understanding of their potential fitness effects. Finally, in Paper IV we show how het genes with pleiotropic effects on sexual recognition lead to the evolution of strong reproductive isolation, and hence speciation. Overall, the results of my thesis highlight the functional intersection between mobile selfish genetic elements and other genes, either selfish or adaptive, and their effects on genome architecture and population structure. Keywords: Podospora, Meiotic drive, Spore killing, vegetative incompatibility, heterokaryon incompatibility, allorecognition, speciation, Transposable elements, selfish genetic elements, fungi Sandra Lorena Ament-Velásquez, Department of Organismal Biology, Systematic Biology, Norbyv. 18 D, Uppsala University, SE-75236 Uppsala, Sweden. © Sandra Lorena Ament-Velásquez 2020 ISSN 1651-6214 ISBN 978-91-513-0921-7 urn:nbn:se:uu:diva-407766 (http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-407766) A mis padres List of Papers This thesis is based on the following papers, which are referred to in the text by their Roman numerals. I Vogan, A.A.*, Ament-Velásquez, S.L.*, Granger-Farbos, A., Sved- berg, J., Bastiaans, E., Debets, A.J., Coustou, V., Yvanne, H., Clavé, C., Saupe, S.J., Johannesson, H. (2019) Combinations of Spok genes create multiple meiotic drivers in Podospora. eLife, 8: e46454 II Vogan, A.A., Ament-Velásquez, S.L., Bastiaans, E., Wallerman, O., Saupe, S.J., Suh, A., Johannesson, H. (-) The Enterprise: A mas- sive transposon carrying Spok meiotic drive genes. Manuscript III Ament-Velásquez, S.L., Vogan, A.A., Wallerman, O., Hartmann, F., Gautier, V., Silar, P., Giraud, T., Johannesson, H. (-) The evolu- tion of the allorecognition gene repertoire in the Podospora species complex. Manuscript IV Ament-Velásquez, S.L., Vogan, A.A., Granger-Farbos, A., Bas- tiaans, E., Martinossi-Allibert, I., Saupe, S.J., de Groot, S., Lascoux, M., Debets, A.J.M., Clavé, C., Johannesson, H. (-) Allorecognition genes drive reproductive isolation in Podospora anserina. Manu- script Reprints were made with permission from the respective publishers. * These authors contributed equally Additional papers The following papers were published during the course of my doctoral stud- ies, but are not part of this thesis. Ament-Velásquez, S.L., Breedy, O., Cortés, J., Guzman, H.M.H.M., Wörheide, G., Vargas, S., (2016). Homoplasious colony morphology and mito-nuclear phylogenetic discordance among Eastern Pacific Octocorals. Molecular Phylogenetics and Evolution, 98: 373–81 Ament-Velásquez, S.L., Figuet, E., Ballenghien, M., Zattara, E.E., Noren- burg, J.L., Fernández-Álvarez, F.A., Bierne, J., Bierne, N., Galtier, N. (2016). Population genomics of sexual and asexual lineages in fissiparous ribbon worms (Lineus, Nemertea): Hybridization, polyploidy and the Me- selson Effect. Molecular Ecology, 25 (14): 3356–69 Contents Introduction ................................................................................................... 11 Intragenomic conflict and meiotic drive as evolutionary forces .............. 12 An observable case of meiotic drive: spore killing in fungi ..................... 17 Examples of spore killers ..................................................................... 18 The protagonists: Podospora anserina and allied taxa ............................ 20 A peculiar life cycle ............................................................................. 22 Reproductive biology of fungi and of P. anserina .............................. 22 To fuse or not to fuse: the heterokaryon incompatibility system ............. 26 NLRs: a recurrent theme in the structure of intracellular guardians .... 29 Research aims ................................................................................................ 32 Summary of results ....................................................................................... 33 The genetic basis and evolution of meiotic drive in Podospora anserina (Papers I and II) ........................................................................................ 33 The intersection between allorecognition genes and other recognition systems in Podospora (Papers III and IV) ................................................ 35 Conclusions and future prospects .................................................................. 38 Svensk sammanfattning ................................................................................. 41 Resumen en español ...................................................................................... 43 Acknowledgments ......................................................................................... 45 Cover explanation ......................................................................................... 54 References ..................................................................................................... 55 Abbreviations DNA Deoxyribonucleic acid bp, kb, Mb Base pair, Kilo base, Mega base het Heterokaryon incompatibility gene Indel Insertion / Deletion TE Transposable element LTR Long terminal region LD Linkage disequilibrium PCR Polymerase chain reaction SNP Single nucleotide polymorphism VI Vegetative incompatibility reaction π Nucleotide diversity θw Watterson’s theta Dxy Average number of pairwise differences Introduction In a report meant to introduce the filamentous fungus Podospora anserina (Ces. Ex Rabenh.) Niessl as a model organism, the German geneticist Karl Esser wrote “The reader may ask, why are these Europeans using such a strange and, from the first glance, rather complicated organism as Podo- spora, and, why do they not integrate into the large family of Neurosporolo- gists?” (Esser, 1969). To answer, he then proceeded to list a number of rea- sons as to why P. anserina is great for research. They included things that are important in model organisms, like a short life cycle and the amenability to mutagenesis, but also other properties like the easy isolation of haploid spores, no asexual propagules to contaminate other plates, and interesting biological aspects of its life cycle. With my work, I wish to add to this list by emphasizing the use of P. anserina as a model organism for the study of fundamental questions in evolution biology. In tune with traditional Podospora literature, the focus of my research is heavily gene-centric. Specifically, I gravitate around two types of genes: selfish and allorecognition genes. Selfish genetic elements (including pro- tein-coding genes) are parasitic units
Load more

Recommended publications
  • Prpsc Prions State of the Art
    Sc PrP Prions State of the Art Edited by Joaquín Castilla and Jesús R. Requena Printed Edition of the Special Issue Published in Pathogens www.mdpi.com/journal/pathogens PrPSc Prions: State of the Art Sc PrP Prions: State of the Art Special Issue Editors Joaqu´ınCastilla Jes ´usR. Requena MDPI • Basel • Beijing • Wuhan • Barcelona • Belgrade Special Issue Editors Joaqu´ın Castilla Jes us´ R. Requena CIC bioGUNE University of Santiago de Compostela Spain Spain Editorial Office MDPI St. Alban-Anlage 66 Basel, Switzerland This is a reprint of articles from the Special Issue published online in the open access journal Pathogens (ISSN 2076-0817) from 2017 to 2018 (available at: https://www.mdpi.com/journal/pathogens/ special issues/prions study) For citation purposes, cite each article independently as indicated on the article page online and as indicated below: LastName, A.A.; LastName, B.B.; LastName, C.C. Article Title. Journal Name Year, Article Number, Page Range. ISBN 978-3-03897-308-9 (Pbk) ISBN 978-3-03897-309-6 (PDF) Cover image courtesy of Jesus´ R. Requena and Joaqu´ın Castilla. Articles in this volume are Open Access and distributed under the Creative Commons Attribution (CC BY) license, which allows users to download, copy and build upon published articles even for commercial purposes, as long as the author and publisher are properly credited, which ensures maximum dissemination and a wider impact of our publications. The book taken as a whole is c 2018 MDPI, Basel, Switzerland, distributed under the terms and conditions of the Creative Commons license CC BY-NC-ND (http://creativecommons.org/licenses/by-nc-nd/4.0/).
    [Show full text]
  • Ascomyceteorg 08-03 Ascomyceteorg
    Podospora bullata, a new homothallic ascomycete from kangaroo dung in Australia Ann BELL Abstract: Podospora bullata sp. nov. is described and illustrated based on five kangaroo dung collections Dan MAHONEY from Australia. The species is placed in the genus Podospora based on its teleomorph morphology and its Robert DEBUCHY ITS sequence from a fertile homothallic axenic culture. Perithecial necks are adorned with prominent simple unswollen filiform flexuous and non-agglutinated greyish hairs. Ascospores are characterized by minute pe- dicels, lack of caudae and an enveloping frothy gelatinous material with bubble-like structures both in the Ascomycete.org, 8 (3) : 111-118. amorphous gel and attached to the ascospore dark cell. No anamorph was observed. Mai 2016 Keywords: coprophilous fungi, Lasiosphaeriaceae, Podospora, ribosomal DNA, taxonomy. Mise en ligne le 05/05/2016 Résumé : Podospora bullata sp. nov. est une nouvelle espèce qui a été trouvée sur cinq isolats provenant d’Australie et obtenus à partir de déjections de kangourou. Cette nouvelle espèce est décrite ici avec des il- lustrations. Cet ascomycète est placé dans le genre Podospora en se basant sur la séquence des ITS et sur l’aspect de son téléomorphe, en l’occurrence un individu homothallique fertile en culture axénique. Les cols des périthèces sont ornés par une touffe de longs poils grisâtres fins, flexueux, en majorité sans ramification et non agglutinés. Les ascospores sont caractérisées par de courts pédicelles et une absence d’appendices. Les ascospores matures sont noires et entourées par un mucilage contenant des inclusions ayant l’aspect de bulles, adjacentes à la paroi de l’ascospore.
    [Show full text]
  • Podospora Anserina Bibliography N° 10 - Additions
    Fungal Genetics Reports Volume 50 Article 15 Podospora anserina bibliography n° 10 - Additions Robert Debuchy Université Paris-Sud Follow this and additional works at: https://newprairiepress.org/fgr This work is licensed under a Creative Commons Attribution-Share Alike 4.0 License. Recommended Citation Debuchy, R. (2003) "Podospora anserina bibliography n° 10 - Additions," Fungal Genetics Reports: Vol. 50, Article 15. https://doi.org/10.4148/1941-4765.1161 This Special Paper is brought to you for free and open access by New Prairie Press. It has been accepted for inclusion in Fungal Genetics Reports by an authorized administrator of New Prairie Press. For more information, please contact [email protected]. Podospora anserina bibliography n° 10 - Additions Abstract Podospora anserina is a coprophilous fungus growing on herbivore dung. It is a pseudohomothallic species in which ascus development results, as in Neurospora tetrasperma but through a different process, in the formation of four large ascospores containing nuclei of both mating types. This special paper is available in Fungal Genetics Reports: https://newprairiepress.org/fgr/vol50/iss1/15 Debuchy: Podospora anserina bibliography n° 10 - Additions Number 50, 2003 27 Podospora anserina bibliography n/ 10 - Additions Robert Debuchy, Institut de Génétique et Microbiologie UMR 8621, Bâtiment 400, Université Paris-Sud, 91405 Orsay cedex, France. Fungal Genet. Newsl. 50: 27-36. Podospora anserina is a coprophilous fungus growing on herbivore dung. It is a pseudohomothallic species in which ascus development results, as in Neurospora tetrasperma but through a different process, in the formation of four large ascospores containing nuclei of both mating types. These ascospores give self-fertile strains.
    [Show full text]
  • Using Phylogenetic Species Recognition to Delimit Species Boundaries Within Lasiosphaeria
    Mycologia, 96(5), 2004, pp. 1106±1127. q 2004 by The Mycological Society of America, Lawrence, KS 66044-8897 Using phylogenetic species recognition to delimit species boundaries within Lasiosphaeria Andrew N. Miller1 Key words: Ascomycetes, b-tubulin, Cercophora, Botany Department, The Field Museum, 1400 S. Lake genealogical concordance phylogenetic species rec- Shore Drive, Chicago, Illinois 60605-2496 and ognition, ITS, LSU, morphological species recogni- University of Illinois at Chicago, Department of tion, phylogenetics, RPB2, Sordariales, species con- Biological Sciences, Chicago, Illinois 60607-7060 cepts, systematics Sabine M. Huhndorf Botany Department, The Field Museum, 1400 S. Lake Shore Drive, Chicago, Illinois 60605-2496 INTRODUCTION The genus Lasiosphaeria previously included numer- Abstract: The genus Lasiosphaeria recently has been ous taxa possessing a broad range of ascomal, asco- circumscribed more narrowly to include ®ve mor- spore and anamorph morphologies. However, its cir- phospecies united by tomentose ascomata containing cumscription recently has been de®ned more nar- yellow centrum pigments. Species boundaries have rowly to include ®ve morphospecies possessing to- not been established and phylogenetic relationships mentose ascomata with yellow centrum pigments have not been clearly de®ned for these morphospe- (Miller and Huhndorf 2004a). The genus presently cies. To delimit species boundaries and determine includes the type, L. ovina (Pers. : Fr.) Ces. & de phylogenetic relationships among species, maximum Not., along with L. glabrata (Fr.) Munk, L. lanuginosa parsimony, maximum likelihood and Bayesian analy- (H. Crouan & P. Crouan) A.N. Mill. & Huhndorf, L. ses were conducted on sequence data from four nu- rugulosa (A.N. Mill. & Huhndorf) A.N. Mill. & Huhn- clear genes, the ribosomal internal transcribed spac- dorf, and L.
    [Show full text]
  • Morinagadepsin, a Depsipeptide from the Fungus Morinagamyces Vermicularis Gen. Et Comb. Nov
    microorganisms Article Morinagadepsin, a Depsipeptide from the Fungus Morinagamyces vermicularis gen. et comb. nov. Karen Harms 1,2 , Frank Surup 1,2,* , Marc Stadler 1,2 , Alberto Miguel Stchigel 3 and Yasmina Marin-Felix 1,* 1 Department Microbial Drugs, Helmholtz Centre for Infection Research, Inhoffenstrasse 7, 38124 Braunschweig, Germany; [email protected] (K.H.); [email protected] (M.S.) 2 Institute of Microbiology, Technische Universität Braunschweig, Spielmannstrasse 7, 38106 Braunschweig, Germany 3 Mycology Unit, Medical School and IISPV, Universitat Rovira i Virgili, C/ Sant Llorenç 21, 43201 Reus, Tarragona, Spain; [email protected] * Correspondence: [email protected] (F.S.); [email protected] (Y.M.-F.) Abstract: The new genus Morinagamyces is introduced herein to accommodate the fungus Apiosordaria vermicularis as inferred from a phylogenetic study based on sequences of the internal transcribed spacer region (ITS), the nuclear rDNA large subunit (LSU), and partial fragments of ribosomal polymerase II subunit 2 (rpb2) and β-tubulin (tub2) genes. Morinagamyces vermicularis was analyzed for the production of secondary metabolites, resulting in the isolation of a new depsipeptide named morinagadepsin (1), and the already known chaetone B (3). While the planar structure of 1 was elucidated by extensive 1D- and 2D-NMR analysis and high-resolution mass spectrometry, the absolute configuration of the building blocks Ala, Val, and Leu was determined as -L by Marfey’s method. The configuration of the 3-hydroxy-2-methyldecanyl unit was assigned as 22R,23R by Citation: Harms, K.; Surup, F.; Stadler, M.; Stchigel, A.M.; J-based configuration analysis and Mosher’s method after partial hydrolysis of the morinagadepsin Marin-Felix, Y.
    [Show full text]
  • Ami1, an Orthologue of the Aspergillus Nidulans Apsa Gene, Is Involved in Nuclear Migration Events Throughout the Life Cycle of Podospora Anserina
    Copyright 2000 by the Genetics Society of America ami1, an Orthologue of the Aspergillus nidulans apsA Gene, Is Involved in Nuclear Migration Events Throughout the Life Cycle of Podospora anserina Fatima GraõÈa, VeÂronique Berteaux-Lecellier, Denise Zickler and Marguerite Picard Institut de GeÂneÂtique et Microbiologie de l'Universite Paris-Sud (Orsay), 91405 France Manuscript received September 22, 1999 Accepted for publication February 3, 2000 ABSTRACT The Podospora anserina ami1-1 mutant was identi®ed as a male-sterile strain. Microconidia (which act as male gametes) form, but are anucleate. Paraphysae from the perithecium beaks are also anucleate when ami1-1 is used as the female partner in a cross. Furthermore, in crosses heterozygous for ami1-1, some crozier cells are uninucleate rather than binucleate. In addition to these nuclear migration defects, which occur at the transition between syncytial and cellular states, ami1-1 causes abnormal distribution of the nuclei in both mycelial ®laments and asci. Finally, an ami1-1 strain bearing information for both mating types is unable to self-fertilize. The ami1 gene is an orthologue of the Aspergillus nidulans apsA gene, which controls nuclear positioning in ®laments and during conidiogenesis (at the syncytial/cellular transition). The ApsA and AMI1 proteins display 42% identity and share structural features. The apsA gene comple- ments some ami1-1 defects: it increases the percentage of nucleate microconidia and restores self-fertility in an ami1-1 matϩ (matϪ) strain. The latter effect is puzzling, since in apsA null mutants sexual reproduction is quite normal. The functional differences between the two genes are discussed with respect to their possible history in these two fungi, which are very distant in terms of evolution.
    [Show full text]
  • Coprophilous Fungal Community of Wild Rabbit in a Park of a Hospital (Chile): a Taxonomic Approach
    Boletín Micológico Vol. 21 : 1 - 17 2006 COPROPHILOUS FUNGAL COMMUNITY OF WILD RABBIT IN A PARK OF A HOSPITAL (CHILE): A TAXONOMIC APPROACH (Comunidades fúngicas coprófilas de conejos silvestres en un parque de un Hospital (Chile): un enfoque taxonómico) Eduardo Piontelli, L, Rodrigo Cruz, C & M. Alicia Toro .S.M. Universidad de Valparaíso, Escuela de Medicina Cátedra de micología, Casilla 92 V Valparaíso, Chile. e-mail <eduardo.piontelli@ uv.cl > Key words: Coprophilous microfungi,wild rabbit, hospital zone, Chile. Palabras clave: Microhongos coprófilos, conejos silvestres, zona de hospital, Chile ABSTRACT RESUMEN During year 2005-through 2006 a study on copro- Durante los años 2005-2006 se efectuó un estudio philous fungal communities present in wild rabbit dung de las comunidades fúngicas coprófilos en excementos de was carried out in the park of a regional hospital (V conejos silvestres en un parque de un hospital regional Region, Chile), 21 samples in seven months under two (V Región, Chile), colectándose 21 muestras en 7 meses seasonable periods (cold and warm) being collected. en 2 períodos estacionales (fríos y cálidos). Un total de Sixty species and 44 genera as a total were recorded in 60 especies y 44 géneros fueron detectados en el período the sampling period, 46 species in warm periods and 39 de muestreo, 46 especies en los períodos cálidos y 39 en in the cold ones. Major groups were arranged as follows: los fríos. La distribución de los grandes grupos fue: Zygomycota (11,6 %), Ascomycota (50 %), associated Zygomycota(11,6 %), Ascomycota (50 %), géneros mitos- mitosporic genera (36,8 %) and Basidiomycota (1,6 %).
    [Show full text]
  • Field Studies in the Lasiosphaeriaceae And
    Field Studies in the Lasiosphaeriaceae and Helminthosphaeriaceae sensu lato. By Ann Bell and Daniel P. Mahoney. 2016. CBS-KNAW Fungal Biodiver- sity Centre, Utrecht, The Netherlands. Pp. 124, 80 figs (78 col.). [CBS Biodi- versity Series no. 15.] ISBN 978-94-91751-05-9. Price: 30 €. Zealand but also from visits to the USA. mycologists as well as professionals to take I am so glad that they did, as now we have an interest in these poorly known fungi. All BOOK NEWS a superbly colour-illustrated account of those working on fungi occurring on dung many of these fungi for the first time. They or dead wood should try and secure a copy. did, however, conclude on morphological The whole is superbly produced, as grounds that the primarily fungicolous we have now come to expect of CBS, but Helminthosphaeriacae appeared to be attention is drawn on the website to the indistinguishable from Lasiosphaeriaceae; it inevitable minor slips all works seem to have will be interesting to see if future molecular despite hours of proof-reading; these are studies can confirm that hypothesis. reproduced below1 (so those with copies can Four keys to the species are provided, annotate them accordingly. with main divisions based primarily on perithecial vestitures (the terminology of Bell A (1983) Dung Fungi: an illustrated guide to which is discussed and illustrated). Species coprophilous fungi in New Zealand. Wellington: descriptions are accompanied by two Victoria University Press. full-colour pages of illustrations, one of Bell A (2005) An Illustrated Guide to the exquisite coloured drawings and the other Coprophilous Ascomycetes of Australia [CBS of colour photographs, including ones in Biodiversity Series No.
    [Show full text]
  • Prions As Protein-Based Genetic Elements
    14 Aug 2002 14:0 AR AR168-MI56-28.tex AR168-MI56-28.sgm LaTeX2e(2002/01/18) P1: IBD 10.1146/annurev.micro.56.013002.100603 Annu. Rev. Microbiol. 2002. 56:703–41 doi: 10.1146/annurev.micro.56.013002.100603 Copyright c 2002 by Annual Reviews. All rights reserved First published online as a Review in Advance on July 15, 2002 PRIONS AS PROTEIN-BASED GENETIC ELEMENTS Susan M. Uptain1 and Susan Lindquist2 1Howard Hughes Medical Institute, Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, Illinois 60637; e-mail: [email protected] 2Whitehead Institute for Biomedical Research, Department of Biology, Massachusetts Institute of Biology, Nine Cambridge Center, Cambridge, Massachusetts 02142; e-mail: lindquist [email protected] Key Words Sup35, Ure2, HET-s, Rnq1, amyloid ■ Abstract Fungal prions are fascinating protein-based genetic elements. They alter cellular phenotypes through self-perpetuating changes in protein conformation and are cytoplasmically partitioned from mother cell to daughter. The four prions of Saccharomyces cerevisiae and Podospora anserina affect diverse biological pro- cesses: translational termination, nitrogen regulation, inducibility of other prions, and heterokaryon incompatibility. They share many attributes, including unusual genetic behaviors, that establish criteria to identify new prions. Indeed, other fungal traits that baffled microbiologists meet some of these criteria and might be caused by prions. Recent research has provided notable insight about how prions are induced and prop- agated and their many biological roles. The ability to become a prion appears to be evolutionarily conserved in two cases. [PSI+] provides a mechanism for genetic vari- ation and phenotypic diversity in response to changing environments.
    [Show full text]
  • A Reinterpretation of the Pseudo-Bombardioid Ascomal Wall in Taxa in the Lasiosphaeriaceae
    ©Verlag Ferdinand Berger & Söhne Ges.m.b.H., Horn, Austria, download unter www.biologiezentrum.at A reinterpretation of the pseudo-bombardioid ascomal wall in taxa in the Lasiosphaeriaceae Andrew N. Miller1'* 1 Field Museum of Natural History, Botany Department, Chicago, Illinois 60605-2496, USA and University of Illinois at Chicago, Department of Biological Sciences, Chicago, Illinois 60607-7060, USA Miller, A. N. (2003). A reinterpretation of the pseudo-bombardioid ascomal wall in taxa in the Lasiosphaeriaceae. - Sydowia 55 (2): 267-273. A coriaceous pseudo-bombardioid ascomal wall containing a central layer composed of thick-walled, gelatinized cells has been described in nine species in the Lasiosphaeriaceae (Sordariales). Three different methods of sectioning asco- mata were employed to investigate the composition of this wall layer. Although this wall layer has previously been described as being composed of isodiametric cells, sections made using a freezing microtome revealed that it was actually com- posed of interwoven hyphae. Thus the term pseudo-bombardioid should be emen- ded to describe a non-stromatic ascomal wall containing a gelatinized layer com- posed of interwoven, thin-walled hyphae. Keywords: Ascomycetes, Arnium, Bombardia, Bombardioidea, Cercophora, Podospora, terminology. A unique type of coriaceous ascomal wall referred to as a pseudo-bombardioid wall was defined by Lundqvist (1972: 17) in his seminal work on Nordic Sordariaceae as "a multi-layered, non-stro- matic wall with a second pseudo-parenchymatous layer with very thick-walled, gelatinized cells". Lundqvist (1972: 17) distinguished it from the bombardioid wall, which he described as "a multi-layered wall with at least two outer, stromatic layers, the second of which is fibrous and cartilaginous".
    [Show full text]
  • Ribosomal RNA Modulates Aggregation of the Podospora Prion Protein HET-S
    International Journal of Molecular Sciences Article Ribosomal RNA Modulates Aggregation of the Podospora Prion Protein HET-s Yanhong Pang y, Petar Kovachev and Suparna Sanyal * Department of Cell and Molecular Biology, Uppsala University, Box-596, Biomedical Center, 751 24 Uppsala, Sweden; [email protected] (Y.P.); [email protected] (P.K.) * Correspondence: [email protected] Present address: Department of Molecular Sciences, Uppsala Biocenter, Swedish University of Agricultural y Sciences, 750 07 Uppsala, Sweden. Received: 25 August 2020; Accepted: 28 August 2020; Published: 1 September 2020 Abstract: The role of the nucleic acids in prion aggregation/disaggregation is becoming more and more evident. Here, using HET-s prion from fungi Podospora anserina (P. anserina) as a model system, we studied the role of RNA, particularly of different domains of the ribosomal RNA (rRNA), in its aggregation process. Our results using Rayleigh light scattering, Thioflavin T (ThT) binding, transmission electron microscopy (TEM) and cross-seeding assay show that rRNA, in particular the domain V of the major rRNA from the large subunit of the ribosome, substantially prevents insoluble amyloid and amorphous aggregation of the HET-s prion in a concentration-dependent manner. Instead, it facilitates the formation of the soluble oligomeric “seeds”, which are capable of promoting de novo HET-s aggregation. The sites of interactions of the HET-s prion protein on domain V rRNA were identified by primer extension analysis followed by UV-crosslinking, which overlap with the sites previously identified for the protein-folding activity of the ribosome (PFAR). This study clarifies a missing link between the rRNA-based PFAR and the mode of propagation of the fungal prions.
    [Show full text]
  • The Genus Podospora (Lasiosphaeriaceae, Sordariales) in Brazil
    Mycosphere 6 (2): 201–215(2015) ISSN 2077 7019 www.mycosphere.org Article Mycosphere Copyright © 2015 Online Edition Doi 10.5943/mycosphere/6/2/10 The genus Podospora (Lasiosphaeriaceae, Sordariales) in Brazil Melo RFR1, Miller AN2 and Maia LC1 1Universidade Federal de Pernambuco, Departamento de Micologia, Centro de Ciências Biológicas, Avenida da Engenharia, s/n, 50740–600, Recife, Pernambuco, Brazil. [email protected] 2 Illinois Natural History Survey, University of Illinois, 1816 S. Oak St., Champaign, IL 61820 Melo RFR, Miller AN, MAIA LC 2015 – The genus Podospora (Lasiosphaeriaceae, Sordariales) in Brazil. Mycosphere 6(2), 201–215, Doi 10.5943/mycosphere/6/2/10 Abstract Coprophilous species of Podospora reported from Brazil are discussed. Thirteen species are recorded for the first time in Northeastern Brazil (Pernambuco) on herbivore dung. Podospora appendiculata, P. australis, P. decipiens, P. globosa and P. pleiospora are reported for the first time in Brazil, while P. ostlingospora and P. prethopodalis are reported for the first time from South America. Descriptions, figures and a comparative table are provided, along with an identification key to all known species of the genus in Brazil. Key words – Ascomycota – coprophilous fungi – taxonomy Introduction Podospora Ces. is one of the most common coprophilous ascomycetes genera worldwide, rarely absent in any survey of fungi on herbivore dung (Doveri, 2008). It is characterized by dark coloured, non-stromatic perithecia, with coriaceous or pseudobombardioid peridium, vestiture varying from glabrous to tomentose, unitunicate, non-amyloid, 4- to multispored asci usually lacking an apical ring and transversely uniseptate two-celled ascospores, delimitating a head cell and a hyaline pedicel, frequently equipped with distinctly shaped gelatinous caudae (Lundqvist, 1972).
    [Show full text]